On the GL X3000, the Web UI only allows setting the fan start temperature as low as 70°C. At first glance that feels a bit high, but it is probably fine.

GIF of John Cena looking skeptical and saying Are you sure about that?

Are you sure about that?

The AP MT7981B is specified for an operating temperature range of -40°C to 125°C, so 70°C is well within spec [1]. Still, I wanted the fan to kick in earlier because I was dealing with unwanted random restarts and wanted to reduce heat as a possible factor.

Mine was idling at around 65°C, so waiting until 70°C meant the fan would barely ever run.

Step 1: Connect via SSH

ssh root@192.168.8.1

Step 2: Edit the fan config

vi /etc/config/glfan

You should see something like this:

config globals 'globals'
    option enabled '1'
    option sysfs '/sys/devices/virtual/thermal/thermal_zone0/temp'
    option warn_temperature '75'
    option div '1000'
    option temperature '50'

The setting that controls when the fan starts is option temperature. Change it to your preferred threshold. Save and exit.

Step 3: Restart the fan service

/etc/init.d/gl_fan restart

Done. The fan should now start at your new threshold.

Reference

  1. AP Datasheet: MT7981B Wi-Fi 6 Platform (one.openwrt.org)